Topic summary
Indefinite pitch
Extracted from the Wikipedia article Pitch (music).
Definite and indefinite pitch
Not all musical instruments make notes with a clear pitch. The unpitched percussion instruments (a class of percussion instruments) do not produce particular pitches. A sound or note of definite pitch is one where a listener can possibly (or relatively easily) discern the pitch. Sounds with definite pitch have harmonicfrequency spectra or close to harmonic spectra.